Liquefaction – Potential Dangers of Indonesian Bauxite
12 July 2013
Members will be aware of the dangers associated with the carriage of cargoes that can liquefy from the various Circulars, News Alerts and Stop Loss articles issued by the Club over recent years. The primary focus of concern has been in respect of the carriage of iron ore fines from India and Brazil, as well as nickel ore from the Philippines and Indonesia.
However, the Club has previously reported on possible liquefaction of Bauxite cargoes loaded in Brazil (for the relevant alert, please click here). Recently, the Club has learned of the potential risks arising from the practice of using water cannons to wash Bauxite fines and lumps through sieves in mines in Indonesia. This process significantly increases the moisture content of the cargo, reportedly to approximately 15% by the time the Bauxite is placed in the storage area. This changes the properties of the cargo from one with a low moisture content that is not ordinarily prone to liquefaction, to a cargo which may liquefy during a voyage. Liquefaction of cargo results in cargo shifting and loss of ship stability, a major cause of marine casualties.
As Members may already be aware, Bauxite is not a cargo one would ordinarily expect to be prone to liquefaction. The IMSBC Code as a Group C cargo i.e. a cargo not liable to liquefy but this categorisation is based on the Bauxite cargo having a moisture content between 0% and 10% consisting of 70%-90% lumps varying in size between 2.5 and 500 mm and 10%-30% powder. As we understand it the process that takes place in Indonesia of sieving the cargo to reduce lumps to below 100mm, not only reduces the particle size of the cargo (possibly to smaller than that specified in the IMSBC Code) but also increases the moisture content to that exceeding the levels specified in the IMSBC Code.
Members should therefore remain vigilant at all times with Bauxite cargoes. Members are reminded of Paragraph 2.1 of Appendix 3 of the IMSBC Code which states that "many fine-particled cargoes, if possessing a sufficiently high moisture content, are liable to flow. Thus any damp or wet cargo containing a proportion of fine particles should be tested for flow characteristics prior to loading". In particular, Members should ensure they do not take the shipper's cargo declaration at face value (either as regards the description of the cargo, how it is treated under the IMSBC Code, or the moisture content).
If Members are in any doubt as to the authenticity of the cargo declaration or any of the details provided therein when Bauxite cargoes are to be loaded in Indonesia, the earliest possible consideration should be given to contacting the Club so that independent tests may, if considered necessary, be conducted in order to determine the true nature of the cargo to be loaded and its suitability for carriage.